un task Frank-%s" %(os.getpid())
? ? start = time.time()
? ? time.sleep(random.random() * 20)
? ? end = time.time()
? ? print 'Task Frank runs %0.2f seconds.' %(end - start)
? ? ? ?
if __name__=='__main__':
? ? function_list=? [Lee, Marlon, Allen, Frank]
? ? print "parent process %s" %(os.getpid())
? ? pool=multiprocessing.Pool(4)
? ? for func in function_list:
? ? ? ? pool.apply_async(func)? ? #Pool执行函数，apply执行函数,当有一个进程执行完毕后，会添加一个新的进程到pool中
? ? print 'Waiting for all subprocesses done...'
? ? pool.close()
? ? pool.join()? ? #调用join之前，一定要先调用close() 函数，否则会出错, close()执行后不会有新的进程加入到pool,join函数等待素有子进程结束
? ? print 'All subprocesses done.'
一次执行结果
parent process 7704
Waiting for all subprocesses done...
Run task Lee-6948
Run task Marlon-2896
Run task Allen-7304
Run task Frank-3052
Task Lee, runs 1.59 seconds.
Task Marlon runs 8.48 seconds.
Task Frank runs 15.68 seconds.
Task Allen runs 18.08 seconds.
All subprocesses done.
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